The rendezvous and docking/undocking of a space vehicle with a space station or another space vehicle requires the successful operation of many complex systems. These include systems for controlling the relative maneuvering and alignment of the spacecraft, spacecraft coupling and decoupling mechanisms, and shock attenuating and absorbing systems for reducing impact loads and for sustaining tension loads in holding the spacecraft together after initial engagement. An important consideration and frequently a requirement in the design of such systems is an accommodation for the in-flight transfer of personnel and cargo. Heretofore, docking structure designs which have been proposed to meet this requirement, provide for combined transfer tunnel and docking mechanisms in the form of rigid structures which require considerable support structure of large size and mass and relatively large high-energy shock attenuation devices. In addition, previous docking systems have usually required head-on approaches and very accurate attitude and rate control so that the docking procedures require intensive training of personnel, are very time consuming, and utilize significant amounts of propellants in space vehicle maneuver and in operation of the attitude controls system. A further problem to be encountered during a docking attempt between a space vehicle and a space station is presented by the large offset between the vehicle center of mass and the centerline of the docking mechanism which can cause a large jackknife attitude excursion of the vehicle after the docking impact. Heretofore, these problems have not been successfully addressed by the prior art devices.
A flexible tunnel structure for interconnecting a cargo module with a space vehicle is disclosed in U.S. Pat. No. 3,952,976. The tunnel structure disclosed therein is comprised of serially arranged frame members in an accordion-like tubular housing which can be elongated or shortened by means of a cable system to move in either a linear direction or along a single controlled arc.
Other space vehicle docking mechanisms are disclosed in U.S. Pat. Nos. 3,391,888; 3,608,848; 3,737,117; 3,753,536; 3,820,741; 4,219,171, and 4,682,745 which are rigid structures with associated impact shock attenuation means, and do not provide means for the in-flight transfer of cargo and personnel between the docked vehicles.